26 
T. G. HALLE, 
(Schwed. Südpolar-Exp. 
from the Jurassic of Oregon; but his figures, which appear to represent fertile fronds, 
are not quite convincing. A form with broad segments has been described by Berry 
(1911, p. 231; pi. 23, figs. 3, 4) from the Lower Cretaceous of Maryland. 
Sphenopteris Nordenskjöldii n. sp. 
PL 3, figs. 7, 8. 
The specimens shown in pi. 3, figs. 7 and 8, although presenting some resem- 
blance to Spheiiopteris Goepperti^ seem to belong to a different species and cannot 
be identified with any previously described form. They have therefore been made 
the types of a new species. 
Frond thin and filmy, tri- or quadripinnate. Pinnae with flexuous, winged 
rachises, dissected in a pseudo-dichotomous manner. Ultimate segments narrow and 
linear, each with a strong single vein persisting to the somewhat obtuse apex. 
In the general habit, this species shows a great superficial resemblance to some 
forms of Sphenopteris Goepperti. A closer examination, however, reveals an import- 
ant difference in regard to the dissection of the frond. The specimens shown in 
pi. 3, figs. 7 and 8, whether they are fronds or pinnae, are pinnately divided. In 
the pinnae of higher order, however, the lower segments are much more strongly 
developed than the higher ones, and as the rachises are winged and flexuous and 
are not well marked off from the segments, the result is a pseudo-dichotomous dis- 
section which has in many cases the appearance of true dichotomy. This feature is 
especially evident in the last segmentations and is w'ell seen, for instance, in one of 
the segments to the right in fig. 7. The ultimate segments are always linear and 
not cuneate, and are characterized by a strong median vein. A feature common to 
all the few specimens of this species is the very thin and filmy nature of the frond, 
as evinced by the aspect of the impressions. 
Except the superficial resemblance to Sphenopteris Goepperti, the present form 
shows no close agreement with any known Mesozoic species. One of the figures 
given by RaciborSKI (1894; pi. 14, fig. 20) of his Hynienophyllites {r) Zeilleri is 
somewhat similar; but the other specimens figured by the same author are quite 
different and have certainly nothing to do with the Antarctic species. 
Sphenopteris Nauckhoffiana (Hr). 
PI. 3, figs. 26, 26 a\ te.xt-fig. 6. 
Asplénium Naiickhoffimni/n, Heer 1880 p. 3: pi. i, figs. 9 — 12. 
The frond shown in pi. 3, fig. 26, and some smaller fragments — two of w'hich 
are shown in te.xt-fig. 6 a and b — are no doubt identical with Heer’s Asplenmrn 
Nauckhoffiannm from the lowermost Cretaceous of Pattorfik in West Greenland. 
